Crafting Dynamic Next.js 13 Applications

Strategies and insights for building dynamic Next.js 13 applications.

Introduction

With the release of Next.js 13, the development landscape saw the advent of a refined file system routing mechanism. This update not only brings enhanced flexibility but also introduces more dynamic routing possibilities. A significant change in this version is the evolution from client components to server components.

Client Components vs. Server Components

The primary distinction between client and server components lies in their rendering domain. Traditional components render on the client side, whereas server components take the lead on the server before the content reaches the client. This server-side rendering ensures a rapid initial page load. Furthermore, server components have the capability to fetch data directly from databases and internal APIs, which can then be relayed to client components.

// Server Component
function ServerComponent() {
  const data = fetchDataFromDatabase(); // fetch data from database
  return <div>{data}</div>;
}

// Client Component
'use client';
function ClientComponent() {
  // Hooks and other client-side logic
  return <div></div>;
}

Debunking the Client Component "Myth"

A common misconception within the Next.js community is the belief that client components are solely rendered on the client side. This oversight can cause developers to underestimate the capabilities of client components in server-side rendering contexts.

In truth, client components in Next.js are adaptable, rendering on both the server and the client. When a Next.js page is initially accessed, even the client components within that page undergo server-side rendering. This content, once rendered on the server, is dispatched to the client, ensuring a swift initial page load and enhanced SEO advantages. The key difference emerges in subsequent interactions: client components, in contrast to server components, don't cache their server-rendered output. This implies that subsequent requests or interactions trigger rendering and data fetching (if applicable) on the client side.

Recognizing this dual functionality of client components is crucial. It empowers developers with the flexibility to tailor rendering based on their application's specific demands. Whether it's capitalizing on server-side rendering for the initial page loads or depending on client-side rendering for dynamic content updates, client components cater to both scenarios seamlessly.

I will delve deeper into both approaches in the subsequent sections.

Challenges with Caching

While server components enhance the codebase and offer adaptability, Next.js 13 introduces a notable challenge with caching. Contrary to traditional web applications where each request prompts a fresh server render, Next.js 13 caches the rendered page, delivering it for all following requests. This methodology is ideal for static platforms like blogs or e-commerce sites. However, it presents hurdles for dynamic platforms, such as social media or dashboard applications.

Strategies for Dynamic Web Applications

For developers keen on crafting dynamic web applications using server components, two primary strategies emerge:

1. The 1:1 Components Approach

This strategy fosters a 1:1 relationship between client and server components. Data procured on the server is relayed to the client component as its foundational state. The client component can then execute traditional data fetching to refresh its state if required. This method ensures that the server's data isn't prematurely deemed as the latest, facilitating continuous client-side data updates. It also allows Next.js to server-render the page with the initialData prop, ensuring it's present when the client component mounts.

// page.tsx
import { ClientComponent } from './_client';

function ServerComponent() {
  const serverData = fetchDataFromDatabase();
  return <ClientComponent initialData={serverData} />;
}

// _client.tsx
'use client';
export function ClientComponent({ initialData }) {
  const [data, setData] = useState(initialData);
  useEffect(() => {
    fetchDataAndUpdateState(setData);
  }, []);
  return <div>{data}</div>;
}

2. The 0:1 Components Approach

Here, the emphasis is exclusively on client components, sidelining server components. This conventional approach is even endorsed by the Next.js team for those transitioning from the pages routing system to the revamped file system routing. As explained earlier, a widespread misbelief is that client components render only on the client. In actuality, they also undergo server-side rendering before being dispatched to the client. However, they aren't cached and can't fetch data from databases or internal APIs during their server-side rendering phase. This essentially means that only the markup, paired with the available data, is rendered.

// page.tsx
'use client';
function ClientComponent() {
  const [data, setData] = useState('I like trains');
  useEffect(() => {
    setData('I like turtles');
  }, []);
  return <div>{data}</div>;
}
 // Results in: <div>I like trains</div> during server-side rendering
 // Results in: <div>I like turtles</div> after client-side hydration

Conclusion

The debut of the new file system routing in Next.js 13 has sparked extensive discussions. The choice between the strategies largely hinges on the application's specific needs and the developer's familiarity with the techniques. With insights from the Next.js documentation, developers can make well-informed decisions, ensuring peak performance and an enriched user experience for their applications.